Problem: Simplify the following expression: $t = \dfrac{q}{2} - \dfrac{q}{6}$
Solution: In order to subtract expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $2$ and $6$ $\lcm(2, 6) = 6$ $ t = \dfrac{3}{3} \cdot \dfrac{q}{2} - \dfrac{1}{1} \cdot \dfrac{q}{6} $ $t = \dfrac{3q}{6} - \dfrac{q}{6}$ $t = \dfrac{3q -q}{6}$ $t = \dfrac{2q}{6}$ Simplify the expression by dividing the numerator and denominator by 2: $t = \dfrac{q}{3}$